I'm a .45 guy but I also think that modern bullet construction has indeed improved the performance of the 9mm, making it more than adequate for self defense. The 2 bullets that I prefer are the Federal HSTs, and the Speer Gold Dots. Both are available in different weights here:http://mahsupplies.net/

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I think that one of the notions common to the anti-gunner is the idea that being a victim is 'noble'; as if it is better to be noble in your suffering than disruptive in your own defense.

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Underwood's 147 grain +P+ Gold Dots are the closest thing. They clock in at around 1150 fps out of a Glock 19. Here is a video where the bullett expanded to I believe .79 inches and penetrated over 12 inches from what I remember.

I don't know about you guys but when I look at the picture above . I see the 45 has double the temporary cavtition and almost double the pemanent cavity .

Interestingly enough, most ME's can not differentiate a .22, .380, 9mm, .40 or .45 wound without examining the projectile.

I switched from 45ACP to 9mm long ago.

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I think that one of the notions common to the anti-gunner is the idea that being a victim is 'noble'; as if it is better to be noble in your suffering than disruptive in your own defense.

Actual performance of roughly analogous rounds in the 9/40/45 range exhibit almost identical wound profiles in actual human beings. Forensic pathologists won't even mention caliber in their reports as such, preferring language such as "consistent with a handgun wound". Without an actual recovered projectile, there is no way to really tell.

If you are talking strictly FMJ rounds, consider that 9mm is realy 9.01mm, and .45ACP is really 11.5mm. so we're arguing about 2.49mm; about the thickness of two human fingernails. If you think that takes something from "meh" to "awesome man stopper" ... There will be greater variance in the wound channel based upon the physical makeup of the person shot than based upon the caliber of the round.

Are there differences? Of course there are. Brief primer: diameter alone is a meaningless measurement for the problem, cross-sectional area (and yes you need diameter or radius to calculate it) is more important. Mass is important, but far less than velocity.

Take the following examples:

A 230gr projectile @ 1000fps = 510 ftlbs of force.

A 124gr projectile @ 1000fps = 275 ftlbs of force.

... because mass has a linear effect on energy. Of course .45ACP rounds and 9mm rounds don't typically have the same velocities.

So, so we need a more typical example:

A 230gr projectile @ 850fps = 368 ftlbs of force.

A 124gr projectile @ 1300fps = 465 ftlbs of force.

Now, the above is simply a comparison based upon military specs for 230gr .45ACP ball ammo and 124gr 9mm NATO FMJ, but the point remains the same: velocity is much bigger determiner of energy than mass or cross-sectional area. The NATO 9mm simply has more energy than milspec .45ACP, but energy isn't the whole story.

What .45ACP has going for it is conservation of momentum, as a effect of greater mass. This is why a slower round with less energy can do as good a job as something faster/lighter. Reverse that if you need to do so for emotional comfort.

The 45 does the job by retaining momentum upon impact. The 9mm does it's job by having more energy upon impact to begin with. There are some differences or advantages at the margins to either depending upon what/who exactly you are shooting. They both "work" about the same, as every verifiable test/study/experiment has repeatedly shown.

Is there a difference? Sure ... .45ACP is more easily defeated by soft body armor than 9mm, for instance. On the other hand, someone wearing a rifle plate would feel a greater impact with .45ACP than 9mm.

My point is that it a whole lot of stressing about something that will never, ever make a difference in a gun fight or shooting. Choose whatever you like and learn to shoot it well. That's a far better use of time than stressing over something that is essentially a non-issue, and pretty much settled science outside of gun forums.

I know that physics is boring, and that some people prefer to note guns/calibers used by famous personalities and "been there, done that" guys. The following is a list of calibers and guns chosen by certain famous “cool gun guys” for their own personal self-defense. This information has been culled from various public sources, but cannot be guaranteed 100% at any given time. Also, it’s well known that many of these persons use other calibers or guns in competition or when teaching, and that many have sponsorships with various companies. No meaning is implied regarding the effectiveness of any particular caliber, round or handgun … draw whatever conclusions you wish. (Last updated 09/12/2012):

Shot placement is king as always qouted. I personally like the .45acp. It has been known to not bounce or ricochet off a skull as the 9mm. How are the odds on a 9mm ricocheting off someones skull? Probably slim and none but its still possible. Theres other incidents with 38 calibur shootings my father and stepmother have saw while they were detectives that made them switch and stay mainly with the .45 but now a days its mostly preference. After 1000s of rounds with a .357 most people can fire pretty fast with it but its just takes practice.

Cross-sectional area is a function of diameter so it is kinda hard to understand how you can dismiss it and then say that a cross-sectional area is more to the point.

It's not a question of "dismissing" it, rather a point that it's not the important factor in play. You can derive cross-sectional area starting with the radius as well ... it's just an innumerate way to look at the problem.

It also plays against a general poor understanding of physics and body structures. You aren't any more likely to be significantly harmed if stabbed with a 10ga needle than a 20ga needle, for instance ... even though one is well over twice the diameter of the other. They are both within a range where the body's mechanisms deal with those wounds in about the same way.

People get hung up on trivial measurements which don't adequately describe the whole problem. What's a "better" projectile: .40S&W or 10mm? ... many will not realize that they are the same danged bullet, loaded into different cartridges. Did the diameter of the bullet tell us anything meaningful?

It's the same thing with the most common handgun rounds. They all produce wounds within such a small range of difference that they are essentially "the same thing", as far as the body is concerned. 9/40/45 are all attempts to balance and optimize various factors in a hand-sized weapon. If you go too far from those design boundaries in one direction or another to make some important "gain", you begin to lose something just as important somewhere else. That's one reason why all of the common calibers are within 2mm or so, diameter-wise.

Any way you slice it that's a powerful round. The only .45ACP loads that shade it are equally "overpressure" loads.

Velocity is everything...proof? We don't roll 2 ton balls at 5mph to take out a tank. Instead we fire light (18 lb) APHVDS rounds at nearly 6,000fps for a "mere" 9 MILLION lb-ft of kinetic energy. By comparison that 2 ton ball rolling at 5mph would generate a piddling 1,672 lb-ft of kinetic energy. A CAR rolling up against an M1 Abrams at 5mph might jolt it enough for the occupants to notice, but it sure won't harm it.

Big bullets moving slow was what the world HAD back in the blackpowder era. We were supposed to have moved forward since then.

If the myth of the .45ACP is to be validated, then it would be a better manstopper than the .30'06 based on launching a larger diameter bullet, of greater mass. I doubt even the most ardent "believer" would suggest the .45ACP is a better manstopper than the .30'06 at ANY range.
When bullets have terminal striking velocity above 1300fps they begin to do damage far out of proportion to their caliber and mass.

But as most will agree...whether your choice is the 9mm or .45ACP, either is a good choice.

With modern, premium ammo, all of the "service" cartridges (.38 Spl +P, 9mm, .357 Sig, .40 S&W, .45 GAP, and .45 ACP) perform much more alike than differently and that is because they are designed to. Nearly all of these cartridges will reliably expand to 1.5-2x original diameter and penetrate 12-16" in both bare gelatin and gelatin covered with four layers of denim. The real differences in how these cartridges perform is not in their terminal ballistics, but in their performance after penetrating intermediate barriers such as sheet steel, auto glass, ply wood, and sheet rock and in how quickly and accurately the shooter can fire them. Most people are best armed with whichever of the above cartridges they can shoot the most quickly and accurately from their chosen handgun.

It's not a question of "dismissing" it, rather a point that it's not the important factor in play. You can derive cross-sectional area starting with the radius as well ... it's just an innumerate way to look at the problem.

That is nonsense. Diameter is an important factor in the determination of cross-sectional area. In fact, it is the main determinant since п is nothing more than a constant.

Radius is simply one half of the diameter.

The formula for cross-sectional area is

пr²

or, if you wanna express it terms of diameter

п(½D)²

because r = ½D

Any fourth grader can tell you this.

Either way you must use some function of the diameter of the bullet's expansion face to determine the cross-sectional area of the circular face. For this reason, it is the most important factor in play. You CANNOT determine the cross-sectional area of a bullet without it.

... Either way you have to use some function of the diameter of the bullet's expansion face to determine the cross-sectional area of the circular face. For this reason, it is the most important factor in play. ...

You're missing the point. It's not a matter of diameter being important (or not) in terms of calculating cross-sectional area, it's a matter of diameter being insignificant to the larger problem within the range of possible values.

My point regarding diameter specifically is that it doesn't really tell you anything. If the important factor is cross-sectional diameter, why not just not that in the first place? Doing otherwise serves to obfuscate the underlying physics by suggesting that the problem is much simpler than it is. This is one of the giant reasons why things like the Thatcher formula, the Taylor formula ... and whole host of others ... are utter nonsense.

If you want to get into metrology and physics, the very first thing of importance is to make sure you have adequately described the problem in terms of known physical principles, and secondly to be certain you are measuring the right thing. Everytime I see someone use diameter in some supposed calculation of internal, external or terminal ballistics ... well, I know it's going to be a gun guy, not a physicist or metrologist.

I'm not going to stoop to the level of insult based upon some reference to a grade level. I'll just note that I do this for a living, and a number of institutions like NASA, IBM and Intel think my work is just fine, thanks.

You're missing the point. It's not a matter of diameter being important (or not) in terms of calculating cross-sectional area, it's a matter of diameter being insignificant to the larger problem within the range of possible values.

Well, that is not what you said earlier.

And no one here has said that it is the only value of importance either.

Quote:

Originally Posted by zombietactics:

If you want to get into metrology and physics, the very first thing of importance is to make sure you have adequately described the problem in terms of known physical principles, and secondly to be certain you are measuring the right thing. Everytime I see someone use diameter in some supposed calculation of internal, external or terminal ballistics ... well, I know it's going to be a gun guy, not a physicist or metrologist.

Then you haven't seen Bullet Penetration by Duncan MacPherson (an aerospace engineer) or Quantitative Ammunition Selection by Charles Schwartz. Both models offered in their respective books use diameter/cross-sectional area as one of many important factors and both models do a fantastic job (highly correlated and highly accurate) of predicting penetration and mass of the permanent wound cavity.

Quote:

Originally Posted by zombietactics:

I'm not going to stoop to the level of insult based upon some reference to a grade level.

I didn't insult you. I simply stated that fourth graders are taught this very equation and that as such, it is common knowledge. You can dispute the equation all that you wish, but it still stands that A = пr²

Nice post about energy but it completely neglects momentum which is more important in handgun bullets than energy, IMO, especially when it comes to penetration. Mass is more important than velocity when it comes to momentum.

momentum = mass * velocity

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Jim's Rules of Carry: 1. Any gun is better than no gun. 2. A gun that is reliable is better than a gun that is not. 3. A hole in the right place is better than a hole in the wrong place. 4. A bigger hole is a better hole.

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